Hydraulically set well anchors



NOV 8, 1966 I J. HOFFMAN ETAL 3,283,824

HYDRAULICALLY SET WELL ANCHORS Filed Oct. 14, 1963 .'3 Sheets-Sheet lEG@ fr 26' 3 Sheets-Sheet 2 INVENTORS. clqcz HOFF/wmv DE/vznL I/VI L/wvPWA/LE 5y MW rroQ/VEYS NOV- 8, 1966 J HoFFMAN ETAL HYDRAULICALLY SETWELL ANCHORS Filed oct. 14, 196s Nov. 8, 1966 J. HOFFMAN ETAL. 3,283,824

HYDRAULICALLY SET WELL ANCHORS 5 Sheets-Sheet 5 INVENTORS. ziale/6HOFFMQN' DEA/2m. PV: Vw PWN/LE Filed Oct. 14, 1963 5y 776% @j wwwTToQ/VEYS.

United States Patent O 3,283,824 HYDRAUMCALLY SET WELL ANCHRS JackHoffman, Jackson, Miss., and Denzal W. Van Winkle, La Mirada, Calif.,assignors to Baker Oil Tools, Inc., Los Angeles, Calif., a corporationof California Filed Uct. 14, 1963, Ser. No. 315,909 Claims. (Cl.16d-212) The present invention relates to subsurface well boreequipment, and more particularly to anchors adapted to be run and set inwell casing and similar conduit strings disposed in well bores.

Certain types of subsurface well bore apparatus embody gripping elementsthat are expanded outwardly hydraulically against the wall of asurrounding well conduit to anchor the apparatus thereto. Duringlowering of the apparatus through the iiuid in the well conduit,pressure diiierentials can be developed of suliicient extent as toeffect expansion of the gripping elements against the conduit wall. Thesame undesirable action might be produced during elevation of theapparatus through the luid in the well conduit. As a result, the teethof the gripping elements or members slide along the well conduit wall,resulting in their dulling and inability to embed themselvessubsequently in the conduit wall for the purpose of electively anchoringthe apparatus to the well conduit. Heretofore, resistance to outwardexpansion of certain types of hydraulically expandable grippingVelements has been provided by retracting springs. Such springs, however,can only resist compartively low pressure differentials. Despite theirpresence, dulling of the gripping elements still occurs. The spring havethe disadvantage of reducing the hydraulic pressure available forholding the gripping members anchored against the conduit wall. Inaddition, the provision of the springs imposes design limitations on theapparatus, restricting the range of expansion of the gripping membersand the range of conduit sizes in which the same size apparatus can beused etectively.

An object of the persent invention is to provide hydraulically setsubsurface well apparatus having gripping elements held positively inretracted position during lowering or elevating of the apparatus throughfluid in the well bore, or during both lowering and elevating of theapparatus in the well bore.

Another object of the invention is to provide a hydraulically set wellapparatus having gripping elements held positively in retracted positionduring longitudinal movement of the apparatus in the well bore, theelements eing releasable for outward expansion, then being reshiftableto retracted position, and again positively retained in such position.

A further object of the invention is to provide a hydraulically set wellapparatus adapted to be lowered in a well bore on a running-in stringand having gripping elements held positively in retracted position by aholding device, the holding device being positively releasable by alongitudinal force imposed on the running-in string, and the grippingelements being positively retractable from their outwardly expandedposition by a longitudinal force transmitted through the running-instring to the holding device and gripping elements.

An additional object of the invention is to provide a hydraulically setwell apparatus having gripping elements held positively in retractedposition by a holding device which is releasable when the grippingelements are to be expanded hydraulically, and which automaticallyretracts the gripping elements and retains them in retracted positionupon release of the hydraulic expansion force.

Yet another object of the invention is to provide a well apparatushaving gripping elements expandable outwardly by lluid pressure, inwhich the lluid pressure is fully utilized to urge the gripping elementsagainst the confining conduit string in the well bore, inasmuch as theapparatus does not embody spring retracting devices, or the like, actingupon the gripping elements.

Still a further object of the invention `is to provide a well apparatushaving gripping elements expandable outwardly by tluid pressure againtthe wall of a well conduit, the elements having a comparatively largerange of expansion, enabling the same size apparatus to be set in agreater range of conduit sizes.

Another object of the invention is to provide a hydraulically set wellapparatus embodying button or pispiston type of gripping elementsadapted to be positively held in retracted position by a device whichalso serves to maintain the elements properly oriente-d in the body ofthe apparatus.

This invention possesses many other advantages, and has other objectswhich may be made more clearly apparent from a consideration of a formin which it may be embodied. This form is shown in the drawingsaccompanying and forming part of the persent specication. It will now bedescribed in detail, for the purpose of illustrating the generalprinciples of the invention; but it is to be understood that suchdetailed description is not to be taken in a limiting sense, since thescope of the invention is best dened by the appended claims,

Referring to the drawings:

FIGURES la and lb together constitute a combined side elevational viewand longitudinal section through a well packer and anchor apparatusembodying the invention, with the parts in retracted position, FlG. 1bbeing a lower continuation of FIG. 1a;

FIGS. 2a and 2b are views corresponding to FIGS. la and 1b, illustratingthe well packer anchored in packedolf condition againstthe well casing,FIG. 2b being a lower continuation of FIG. 2a;

FIG. 3 is a front Velevational view, on 'an enlarged scale, of a buttonor piston anchor portion of the apparatus, with the retaining device inan intermediate position;

FIG. 4 is a longitudinal section taken along the line 4-4 on FIG. 3;

FIG. .5 is a cross-section taken along the line 5-5 on FIG. 4;

FIG. 6 is an exploded view of a plurality of piston type grippingelements and a retaining and orienting bar used in connection therewith.

The apparatus A illustrated in the drawings is a setdown type of wellpacker 10 combined with an upper anchor portion 11, the apparatus bei-ngadapted to be lowered and elevated through a string of well casing B, orsimilar conduit string7 on a tubular string C, such as a string oftubing, extending to the top of the well bore. Fluid under pressure isadapted to be pumped downwardly through the tubular string and theapparatus, and suc-h fluid under pressure will hydraulically actua-tethe anchor portion 11 of the apparatus to hold it set against the wallof the well casing.

The apparatus includes a central main body or mandrel 12 |having apassage 13 therethrough, the upper portion of the body being threadedlysecured to a body sub 14 having a threaded box 15 for attaching thelatter to the lower pin end 16 of the tubular string C. The mandrelextends downwardly through Ithe entire extent of the apparatus, its mainbody portion being threaded into the upper end of a lower body sub 17,which ,may constitute the terminal porti-on of the apparatus, or, whichmay, if desired, be threadedly secured -to a lower section 18 of tubingor a lower tool.

The upper portion 11 of the apparatus includes an anchor body 19surrounding the mandrel 12 and relatively slidable with respect thereto.This anchor body has a plurality of circumferentially spaced cylindricalbores 20 therethrough, each of which contains -a piston gripping element21 slidable radially therein. The cylindrical bores open to the interiorof the anchor body 19 and also to the exterior thereof. The pistongripping elements have external wickers or teeth 22 facing in an upperdirection to anchor the apparatus to the well casing against upwardmovement.therewithin As shown in the drawings, a plurality of cylinders20 and gripping elements 21 are provided in longitudinal alignment withone another, to increase the number of elements 21 available foranchoring the apparatus in the well casing. Of course, the anchorportion of the apparatus could include only a single set ofcircumferentially spaced gripping elements and cylinders, instead of theplurality of longitudinally spaced sets disclosed.

The piston gripping elements are expanded outwardly whenever fluidpressure differential is present interiorly of the anchor body 19. Inthe specific tool illustrated, such fluid pressure is derived from theexterior of the tool below the anchor portion of the apparatus, whichpressure can pass through an annular by-pass 23 between the anchor body19 and the .periphery of the mandrel 12, the inner portions of thecylinders opening into such annular by-pass. When by-passing of thefluid is prevented, a pressure diierential of the fluid within theby-pass 23 can be built up, such pressure acting through the fluid inthe cylinders 20 upon the hydraulically actuatable pistons 21 to urgethe latter outwardly `and force their teeth 22 into anchoring engagementwit-h the wall of the well casing. Leakage of fluid along each piston isprevented by a suitable piston ring 2li, or side seal ring, on thepiston slidably sealing against the wall of its companion cylinder 20.

The inner mandrel 12 is shiftable longitudinally with respect to theanchor body 19 to open and close the annular by-pass 23. A valve sealring 25 is molded to a ring 26 secured to the upper `mandrel sub 14 byan encompassing upper latch sleeve 27 secured to the sub. The seal ringis adapted to move downwardly into engagement with a valve head 28 atthe upper portion of an anchor body extension 29, projecting upwardlyfrom and secured to the -main portion of the anchor body 19 containingthe cylinders 21B and piston gripping elements 21. The anchor bodyextension 29 is spaced laterally from the periphery of the mandrel toform a :por-tion of the annular by-pass 23, which opens through theupper `end of the valve head 28 when the valve seal 25 is disposedthereabove, as disclosed in FIG. 1a.

When the mandrel 12 is shifted downwardly relative to the anchor body19, its seal ring 25 is moved downwardly into engagement with the valveseat or head 28 to close the upper end of the by-pass 23. This enablesthe fluid pressure below the tool to be increased, passing upwardlythrough the by-pass to the cylinders 2l) for the purpose of expandingthe gripping elements 21 outwardly into anchoring engagement with thewall of the well casing B.

In the specific tool illustrated, the upper anchoring portion 11 of theapparatus is secured to the downwardly anchoring por-tion 10 of theapparatus, which also includes a packing structure 30 for effecting aseal against the wall of the well casi-ng. The lower portion 31 of theanchor body 19 constitutes an upper abutment for the packing structure.This packing structure may include a connector sleeve 32, the upper endof which is threadedly attached to the lower portion 31 of the packerbody, the sleeve being slidable relative to the `mandrel 12 andextending through an initially retracted packing eleme-nt 33 of thestructure, which may be of any suitable type. As shown, the packingstructure includes a rubber or rubber-like packing sleeve engaging thelower end 31 of the anchor body and a gauge ring 34 threadedly securedthereto to provide the proper clearance with the adjacent wall of thewell casing B. The packing eleme-nt surrounds the connector sleeve 32,its lower end engaging a lower abutment 35 th-readedly attached to alower expander 36. This lower abutment 35 has an inwardly directed ange3-7 adapted to contact an outwardly extending ila-nge 38 at the lowerend of t'he connector sleeve 32. When the upper abutment 31, 34 is movedtoward the lower abutment 35, the packing ymember 33 is shortened andexpanded outwardly into sealing engagement with the wall of the wellcasing, as well as again-st the connector sleeve 32, which is disposedin spaced relation to the periphery of the mandrel 12 to provide aportion of the fluid by-pass 23 of the apparatus. When the upperabutment 31, 34 moves toward the lower abutment 35, the lower end of theconnector sleeve can shift downwardly in an annular space 39 between theexpander 36 and the periphery of the mandrel 12.

The lower portion of the expander has an ex-ternal conical or expandersurface 40 tapering in a downward and inward direction and adapted tocoact with companion inner tapered surfaces 41 on the anchor portions 42of rocking types of slips 43 disposed in annular grooves 44 in a sli-pring 45 slidable relative to the mandrel or body 12. Each slip 43 has alower drag portion 46 urged outwardly into frictional engagement withthe wal-l of the casing by a plurality of helical compression springs 47mounted in each groove and bearing against the base of the latter andagainst the drag portions of the slips. The slips are so designed thatthe springs 47 force the drag lportions 46 into full yfrictionalengagement with the wall of the well casing B, rocking the anchorportions 42 inwardly away from the wall of the well casi-ng, thedownwardly facing wickers or tee-th 48 on the anchor portions beingprevented trom contacting the adjacent casing wall. However, when theexpander 36 rnoves downwardly relative to the slips 43, its outertapered surface 40 engages lthe anchor portions 42 and rocks themoutwardly into engagement with lthe casing wall, the rocking action, atrst, occurring about the upper part 49 of the drag portion 46 of eachslip.

The slips 43 are movable jointly downwardly in the casing by a retainerring 5t) mounted in external grooves 51 in the slips between their dragand anchor portions 46, 42, the upper end of this retainer ring beingengaged by an 4outwardly directed lange 52 at the upper end of the slipring 45. Downward movement of the slip ring will cause its lflange 52 toengage :the ring 50, the latter engaging the lower sides of the slipgrooves 51 so as to ypull all of the slips 43 downwardly in the wellcasing. Joint upward movement of the slips is provided by a stop ring 53engaging their lower ends, ythis stop ring being suitably secured to theslip ring, as by means of longitudinally extending screws (not shown).When the apparatus i-s out of the well casing, 4outward movement of theslips 43 is limited by the retainer ring Sli and also by the lowerterminals 54 of the slips engaging a stop rim 55 projecting upwardlyfrom land integral with the stop ring 53.

The lower expander 36 is shiftable downwardly relative t-o the lowerslips 43 to ancho-r them against the well `casing and the upper abutment31, 34 is movable toward the lower abutment 35 to expand the packing 33against the well casing in response to downward movement of the mandrel12 relative to the parts surrounding it. Such relative downward movementalso closes the annular by-pass passage 23 of the apparatus, whichextends from a location below the packing structure 30, as from sideports 56 provided through the expander into the space 39, to the valvehead 28 of the anchor body extension 29. The ability tof the body ormandrel to move downwardly to effect setting of the apparatus isgoverned by a control unit 57 of any suitable type, such as a pin andJ-slot mechanism at the lower portion of the apparatus. As shown, thecontrol unit includes a sleeve 58 suitably secured, as by welding, tothe stop ring 53, this sleeve having a I -slot 59 therein, including ahorizontal lock portion 6i) and a longitudinal release portion 61. Aradi-al pin 62 extends laterally from the lower `sub 17 and is adaptedto move in the J-slot 59. When lthe mandrel 12 is in its upper positionwith the pin 62 in the horizontal por-tion 60 of the slot, downwardmovement of :the mandrel carries all of the part-s surrounding itdownward-ly with it. Downward movement of the slip .assembly 42-53 withthe mandrel is transmitted to the expander 36 through longitudinal limitpins or screws 65 threaded in the lower exp-ander 36 and received withinbores 63 in the sl-ip ring 45, the heads d4 of the screws engaging theupper ends of :the bores or sockets 63. A-s `a result of thisarrangement, downward motion of the slip ring 45 is transmitted throughthe screws 65 to the lower expander. However, upon downward movement ofthe llower exp-ander 36, the screws 65 slide longitudinally in the slipring 45, enabling the expander to move behind the anchor portions 42 ofthe slips and expand them outwardly against the wall of the Well casing.The downward movement of the expa-nder 36 is transmitted through Ithegauge ring 35 to 4the connector sleeve 32 and through the latter to theancho-r body 19. Thus, the Ianchor portion 11 of the apparatus isshifted downwardly with the mandrel 12, the upper valve seal remainingspaced above the valve head 28, the by-pass 23 being in its opencondition.

When It-he mandrel 12 is turned by the tubular string C to shift thelock pin 62 from the horizont-al portion 60 of the -control slot 59 intoalignment with Ithe longitudinal portion 61 of the slot, the mandrel canmove downwardly rela-'tive to the parts surrounding it, since downwardmovement of such latter pa-rts is -resisted by the frictional engagementof the drag portions 46 of the slips `against the wal-l of the wellcasing. Such downward movement of the mandrel brings its va-lve seal 25into engagement with the valve head 28 to close 4the upper end of thefluid -by-pass passage 23, the entire anchor portion 11 of the apparatusshifting downwardly .to carry the packing assembly and expander 36downwardly with it, urging the expander downwardly within the slips 43and shifting the anchor portions 42 of the latter outwardly to embed:their teeth 48 -in the wall of the well casing. Continued downwardmovement of the tubular string C and `mandrel 12 wil-l shift the anchorbody 19 downwardly, urging the uper abutment 31, r34 toward the lowerabutment and shortening the packing element 33, expanding the latterradially outwardly `again-st the wall of :the well casing B.

Fluid under pressure can now be pumped down through the apparatus, suchui-d pressure passing out through the lo-wer end 18 of the tool into thecasing and then upwardly through the by-pass ports 56 into the bypass 23and to the interior of the ycylinders 20 for the purpose of urging thepiston gripping elements 21 outwardly int-o gripping 'engagement with:the wall of the well casing. The piston gripping elements lcan thenprevent upward 'movement of the apparatus A in the well casing under theaction of the duid pressure, downward movement of the apparatus beingprevented by the lower slips 43 and com* pa'nion lower expander 36.

If it is desired to release the .apparatus from the well casing, it isonly necessary -to elevate the tubular string C and mandrel 12, whichwill elevate the valve seal 25 above its companion seat 28, opening theby-pass 23 and allowing the pressure above and below the apparatus toequalize. The mandrel is shifted upwardly runtil ting/ers 79 thereonengage a downwardly facing shoulder 71 on the anchor body extension 29:to pull the anchor body 19 upwardly and the upper Iabutment 311, 34awray from the lower abutment 35, all-owing the packing element 33 toinherently retract from the well casing. 'Ilhe flange 33 on theconnector sleeve engages the -lower abutment or gauge ring 35 to pul-lthe expander 36 upwardly from the slips 43, allowing the springs 47 toreengage the drag portions 46 of the latter fully with the well .casingand rock their anchor portions 42 inwardly from engagement with the welleasing. Upward movement of the expander 36 is transmitted through thescrews 62to the slip ring 45 to cause the entire slip assembly to moveupwardly in the casing. The mandrel can be shifted upwardly, if desired,to relocate the lock pin `62 in alignment with the horizontal portion 60of the slot, the mandrel then being turned to reshift the pin in suchportion. The apparatus can then, if desired, lbe shifted downward-ly inthe well casing, the parts remaining in their retracted positions.

During lowering of the apparatus, and particularly the anchor portion 11thereof, in the well casing, a iluid pressure differential might bedeveloped in the by-pass 23, which iiuid pressure acts on the pistongripping elements 21 and urges them outwardly against the Wall of thewell casing, resulting in sliding of their teeth 22 along the casingwall and their dulling. As a result, the gripping elements or memberswould be less effective, and may, in fact, be ineffective for anchoringthe apparatus against upward movement in the well casing. The uidpressure differential would become more pronounced in the event the toolwere lowered in the well casing with the upper end of the by-pass 23closed. Similarly, with the upper end of the bypass open, elevation ofthe apparatus through the uid in the well casing could develop apressure differential in the fluid in the bypass, which would also urgethe piston gripping elements 21 outwardly against the wall of the wellcasing, resulting in dulling of their teeth 22. In the hydraulic anchorillustrated in the drawings, the gripping elements 21 are prevented frombeing shifted by fluid pressure outwardly against theV wall of the wellcasing, except when outward expansion of such elements against thecasing wall is desired.

As illustrated in the drawings, a retaining housing or sleeve 74 isdisposed around the anchor body, its upper portion 75 beingcircumferentially continuous and providing an enclosure for a helicalcompression retracting spring 76 disposed around the body extension 29.The lower end of the spring acts against the upper end of the anchorbody 19 and its upper end against an inwardly directed flange 7'7 of theretaining sleeve, tending to urge the sleeve '74 in an upward directionand into engagement with an upper ange 75 of the anchor body extension.integral with the circumferentially continuous upper portion 75 of theretaining sleeve are longitudinally extending retaining and orentingmembers or bars 79, there being one bar for each longitudinally alignedset of gripping elements 21. Each bar extends through a companionlongitudinal groove 80 in the anchor body and through the cylinders 2t),the sides 81 of the groove being tapered or convergent in a lateraloutward direction, the bar having companion tapered sides 82 engageablewith such inner tapered sides of the groove to prevent outwarddeiiection or movement of the bar with respect to the anchor body 19.Lateral inward movement of the bar cannot occur in view of itsengagement with the base 83 of the longitudinal body groove.

Each bar 79 extends across longitudinal slots or grooves S4- in theouter portion of a longitudinally aligned set of gripping elements 21,the sides of the bar being engaged by the side walls 85 of the grippingelement grooves so as to maintain the gripping elements properlyoriented within their cylinders 20, with their wickers or teeth 22facing in an upward direction for appropriate embedding in the wall ofthe well casing B. In addition to orienting the gripping elements 21,the bars 79 can selectively retain the gripping elements in their inwardor retracted positions within their respective cylinders, or permittheir outward expansion under the action of fluid pressure within theby-pass 23 and inner portions of the cylinders 2t). As shown, eachgripping member has a retaining, cam or detent portion 86 projectingoutwardly from the base of its groove 84, the lower surface 87 of thedetent being inclined in an upward and outward direction. Each bar has arelease notch or opening 88 in a side thereof into which the detent 36is adapted to project, the bar at the lower end of each notch having acam or retracting surface 89 inclined in an upward and outward directionfor coaction with the inclined detent surface 87. The portion of the barbelow each opening 8S is adapted to engage the detent 36 for the purposeof holding the gripping element 21 fully in its retracted position, andto positively preclude its outward expansion under the action of fluidpressure.

When the retaining sleeve 74- is in its upper position on the anchorbody 19, as disclosed in FIG. la, the retaining or retracting bars 79are disposed across the detents 86 and will positively prevent thegripping elements 21 from shifting outwardly. The development of highpressure differentials within the by-pass 23 will be incapable ofshifting the gripping elements outwardly of their cylinders 20, sincetheir detent portions 86 engage the retaining bars, the bars themselvesengaging the tapered sides 81 of the longitudinal body grooves 8i).

To permit outward expansion of the gripping elements, the retainingsleeve '74 is moved downwardly along the body 19, which correspondinglyshifts the retaining bars 79 downwardly to a position in which therelease notches or openings 88 are aligned with the detents 86 of thegripping elements, the bars no longer being capable of retaining thegripping elements 21 in their retracted positions. Consequently, thedevelopment of fluid pressure in the by-pass 23 will enable suchpressure to act freely on the gripping elements and shift them in alateral outward direction within their cylinders 2th into grippingengagement with the wall of the well casing b. Such outward shifting isfree from restraint by any portions of the apparatus.

Following the equalizing of the pressure internally and externally ofthe tool, the retaining sleeve 74 can be shifted upwardly along the body19, which will cause the cam portions 39 of the bars 79 to engage theinclined surfaces 87 of the detents 86 and force the gripping elements21 radially inwardly of their cylinders 20, the bars sliding fully overthe detents 86 back to the position illustrated in FIG. la, in whichthey will again positively prevent shifting of the gripping elements ina lateral outward direction within their cylinders.

As disclosed in the drawings, the retaining sleeve '74 is normally heldin its upper position holding the gripping elements 21 inwardly of theanchor body 19 by the helical spring 7d. Downward shifting of theretaining sleeve 74, for the purpose of releasing the gripping elements21 for outward expansion hydraulically, is accomplished by the shiftingand latch sleeve 27 threadedly secured to the upper mandrel sub 14, andwhich is also used to hold the valve seal 25 in place, as abovedescribed. The shiftable latch sleeve 27 is of the collet type havingdepending spring-like arms 91 terminating in inwardly directed lingers92 having lower surfaces 93 inclined in a downward and outward directionand adapted to engage a companion inclined or tapered surface 94 at theupper end of the retaining sleeve 74. When the control unit 57 of theapparatus is released by turning the mandrel 12 to Shift the lock pin 62into alignment with the longitudinal portion 61 of the I-slot 59, themandrel or body is shifted downwardly within the parts surrounding it,the shifting latch sleeve 27 moving down with the mandrel and itsfingers 92 engaging the tapered portion 94 of a retaining sleeve flange95. The exertion of sufiicient downward force on the shifting sleevewill cause the fingers 92 to expand outwardly and slide over the flange95, then snapping into a peripheral groove 96 in the retaining sleevetherebelow, the downward motion of the latch sleeve 27 and the mandrel12 then causing the retaining sleeve 74 to shift downwardly against theforce of the helical spring 76 to correspondingly move the retainingbars 79 downwardly along the body of the tool and the gripping elementsto place the notches or openings 88 of the bars in alignment with thedetent portions 86 of the gripping elements. Following such alignment ofthe detent portions with the openings, which frees the gripping elements21 for outward expansion, the valve seal 25 moves downwardly intosealing engagement with its companion valve seat 28 to close the upperend of the by-pass 23.

Continued downward movement of the mandrel 12 will then cause the lowerexpander 36 to shift the slips 43 into engagement with the wall of thewell casing B and will also shorten the packing element 33 and expand itagainst the wall of the well casing. Fluid under pressure can now bepumped downwardly through the tubular string C and mandrel 12, suchfluid pressure passing around the lower portion of the apparatus andentering the by-pass 23 through the expander ports 56, acting on theinner portions of the gripping elements 21 to urge the latter outwardlyand embed their teeth 22 against the wall of the well casing.

When the apparatus A is to be released from the well casing, the tubularstring C and mandrel 12 are elevated in the manner described above inconnection with release of the lower packer portion 10 of the apparatus,the valve seal 25 moving from its seat 2 to equalize the pressure aboveand below the apparatus, the ngers 92 on the latch sleeve engagingv theflange and positively shifting the retaining sleeve '74 upwardly to`cause the cam elements 89 on the bars to engage the inclined faces S7of the detents 86 and shift the gripping elements 21 positively inwardlyto their retracted positions, the bars then sliding across the detentportions 86 to positively retain the gripping elements in retractedposition. Continued elevation of the mandrel effects elevation of theanchor body 19, retraction of the packing element 33 and elevation ofthe expander 36 with respect to the lower slips 43, allowing the latterto reshift to their retracted position. The apparatus A. can now beelevated in the well casing B and removed therefrom at the top of thewell bore, if desired. During such elevation through the iuid in thewell casing, any pressure differential that might tend to develop in theopen by-pass 23 as a result of such movement will be incapable ofinadvertently shifting the piston gripping elements 21 into engagementwith the well casing, since they are positively locked in retractedposition by the retaining and retracting bars 79.

By virtue of the apparatus specifically illustrated and described, thegripping elements 21 can be positively retracted by the taking of adirect pull on the tubular string C. The gripping elements can bereleased to permit their hydraulic outward expansion by taking a directpush on the tubular string C, which is transmitted to the retainingsleeve 74 to insure its downward shifting to a released position. In theabsence of the latch device snapping over the upper flange 95 of theretaining sleeve, but merely engaging its upper end to shift the sleevedownwardly to a gripping element releasing position, the subsequentelevation of the tubular string C and mandrel 12 to remove the valveseal 25 from its companion seat 28 will allow the pressure to equalizeinternally and externally of the cylinders 20 and across the grippingelements 21, which will permit the helical retracting spring 76 toelevate the retaining sleeve 74 and reshift the gripping elements 21 totheir inward positions within the cylinders, the bars 79 then shiftingupwardly fully over the detent portions 86 of the gripping elements topositively hold and lock the latter in their inward positions.

It is thus apparent that an apparatus has been provided in which thehydraulically actuable gripping elements are prevented from beingshifted outwardly during lowering of the apparatus through the fluid inthe well casing, as well as during elevation of the apparatus throughthe uid in the well casing. The gripping elements are positively lockedin their retracted positions by the retaining mechanism, which alsofunctions to orient the gripping elements properly so that their teeth22 always face in the appropriate direction for anchoring engagementwith the wall of the well casing. Once the retaining sleeve 74 has beenshifted to a released position, there are no elements interfering withhydraulic expansion of the gripping elements against the wall of thewell casing. Heretoiore, retracting springs were used to resistexpansion of the gripping elements and to return the gripping elementsto retracted position. The force of such springs had to be overcome bythe hydraulic pressure so that a lesser total hydraulic force wasavailable for holding the gripping elements anchored against the wall ofthe well casing. The absence of restraining springs, and the like,enables the full hydraulic pressure to be available for anchoring thegripping elements against the wall of the well casing. The absence ofthe springs also enables gripping elements to be provided that have alarger radial extent of movement, since there is no interference by thesprings. This permits the use of the same size of equipment foranchoring purposes in a wider range of casings of diering internaldiameters.

We claim:

l. In apparatus adapted to be anchored in a well casing disposed in awell bore: a body having a plurality of bores therein opening to theinterior -of said body; gripping members in said bores expandableoutwardly against the well casing in response to fluid pressure withinsaid body and bores; retaining `means engaging said gripping members forholding said gripping members in retracted position in said bores, saidretaining means being movable longitudinally of said body from holdingengagement with said gripping members; and means for shifting saidretaining means in a direction longitudinally of said body from holdingrelation to said gripping members to permit their outward expansion.

2. In apparatus adapted to be anchored in a well casing disposed in awell bore: a body having a plurality of bores therein opening to theinterior of said body; gripping members in said bores expandableoutwardly against the well casing in response to fluid pressure withinsaid body and bores; retaining means engaging said gripping members forholding said gripping members in retracted position in said bores; andmeans for shifting said retaining means from holding relation to saidgripping members to permit their outward expansion; said retaining meansembodying instrumentalities engageable with said gripping members formoving said gripping members from expanded position to retractedposition.

3. In apparatus adapted to be anchored in a well casing disposed in awell bore: a body; normally retracted casing gripping members on saidbody for anchoring said body in the well casing; hydraulically operablemeans for expanding said gripping members into engagement with the wellcasing; retaining means engaging said gripping members for holding saidgripping members in retracted position on said body and to prevent theiroutward expansion by said hydraulically operable means, said retainingmeans being movable longitudinally of said body from holding engagementwith said gripping members; and means for shifting said retaining meanslongitudinally relative to said body from holding relation to saidgripping members to permit outward expansion of said gripping members.

4. In apparatus adapted to be anchored in a well casing disposed in awell bore: a body; normally retracted casing gripping members on saidbody for anchoring said body in the well casing; hydraulically operablemeans for expanding said gripping members into engagement with the wellcasing; retaining means engaging said gripping members for holding saidgripping members in retracted position on said body and to prevent theiroutward expansion by said hydraulically operable means; and means forshifting said retaining means relative to said body from holdingrelation to said gripping members to permit outward expansion of saidgripping members; said retaining means embodying instrumentalitiesengageable with said gripping members for moving said gripping membersfrom expanded position to retracted position in response to movement ofsaid retaining means relative to said body.

5. in apparatus adapted to be anchored in a well casing disposed in awell bore: a body having a plurality of bores therein opening to theinterior of said body; gripping members in said bores expandableoutwardly against the well casing in response to iiuid pressure Withinsaid body and bones; a mandrel movable within said body; retaining meansengaging said gripping members for holding said gripping members inretract-ed position in said bores; and means operatively connected tosaid mandrel and movable thereby for shifting said retaining means fromholding relation to said gripping members to permit outward expansion ofsaid gripping members.

6. ln apparatus adapted to be anchored in a well casing disposed in awell bore: a body having a plurality of bores therein opening to theinterior of said body; gripping members in said bores expandableoutwardly against the well casing in response to fluid pressure withinsaid body and bores; a mandrel movable within said body; retaining meansengaging said gripping members for holding said gripping members inretracted position in said bores; means operatively connected to saidmandrel and movable thereby for shifting said retaining means fromholding relation to said gripping members to permit outward expansion ofsaid gripping members; and means for shifting said retaining means intoengagement with said gripping members to retract said gripping merribersfrom their expanded position.

7. In apparatus adapted to be anchored in a well casing disposed in awell bore: a body having a plurality of bores therein opening to theinterior of said body; gripping members in said bores expandableoutwardly against the well casing in response to uid pressure withinsaid body and bores; a mandrel movable within said body; retaining meansengaging said gripping members for holding said gripping members inretracted position in said bores; and 'means operatively connected tosaid mandrel and movable thereby for shifting said retaining means fromholding relation to said gripping members to permit outward expansion ofsaid gripping members and to shift said retaining means to holdingrelation to said gripping members to prevent their outward expansion. S.ln apparatus adapted to be anchored in a Well casing'disposed in a wellbore: a body; normally retracted casing gripping members on said bodyfor anchoring said body in the well casing; hydraulically operable meansfor expanding said gripping members into engagement with the wellcasing; a mandrel movable within said body; retaining means engagingsaid gripping members for holding said gripping members in retractedposition on said body and to prevent their outward expansion by saidhydraulically operable means; and means operatively connected to saidmandrel and movable thereby for shifting said retaining means fromholding relation to said gripping members to permit their outwardexpansion. 9. .In apparatus adapted to be anchored in a wellcasingdisposed in a well bore: a body; nonmally retracted casinggrippingmembers on said body for anchoring said body in the well casing;hydraulically operable means for expanding said gripping members intoengagement with the well casing; a mandrel movable within said body;retaining means engaging said gripping members for holding said grippingmembers in retracted position on said body and to prevent their outwardexpansion by said hydraulically operable means; means operativelyconnected to said mandrel and movable thereby for shifting saidretaining means from holding relation to said gripping members to permittheir outward expansion; and means for shifting said retaining meansinto engagement with said gripping members to retract said grippingme-mbers from their expanded position.

lli). In apparatus adapted to be anchored in a well casing disposed in awell bore: a body; normally retracted casing gripping members on saidbody for anchoring said body in the well casing; hydraulically operablemeans for expanding said gripping members into engagement with the wellcasing; a mandrel movable within said body; retaining means engagingsaid gripping members or holding said gripping members in retractedposition on said body and to prevent their outward expansion by saidhydraulically operable means; and means operatively connected to saidmandrel and movable thereby for shifting said retaining means fromholding relation to said gripping members to permit their outwardexpansion and to shift said retaining means to holding relation to saidgripping members to prevent their outward expansion.

lll. In apparatus adapted to be anchored in a well casing disposed in awell bore: a body having a plurality of bores therein opening to theinterior of said body; gripping members insaid bores expandableoutwardly against the well casing in response to fluid pressure withinsaid body and bores; a mandrel movable within said body; retaining meansengaging said gripping members for holding said gripping members inretracted position in said bores; means operatively connected to saidmandrel and movable thereby for shifting said retaining means fromholding relation to said gripping members to permit outward expansion ofsaid gripping members; and spring means for returning said retainingmeans to its holding relation to said gripping members.

12. In apparatus adapted to be anchored in a well casing disposed in awell bore: a body having a plurality of bores therein opening to theinterior of said body; gripping members in said bores expandableoutwardly against the well casing in response to fluid pressure withinsaid body and bores; retaining means externally of said body andengaging said gripping members for holding said gripping members inretracted position in said bores; and means for shifting said retainingmeans longitudinally with respect to said body and gripping members fromholding relation to said gripping members to permit their outwardexpansion.

13. In apparatus adapted to be anchored in a well casing disposed in awell bore: a -body having a plurality of bores therein opening to theinterior of said body; gripping members in said bores expandableoutwardly against the well casing in response to iluid press-ure withinsaid body and bores; said mandrel engageable with said body; retainingmeans extern-ally of said body engaging said gripping mem-bers forholding said gripping members in retracted position in said bores; andmeans operatively connected to said mandrel and movable thereby forShiit- -i-ng said retaining means from holding relation to said grippingmembers to permit their outward expansion.

i. In apparatus adapted to be anchored in a well casin-g disposed in awell bore: a body having a plurality of bores therein opening `to theinterior of said body; gripping members in said bores expandableoutwardly against the well casing in response to fluid pressure withinsaid body and bores; said gripping members having longitudinal slots intheir outer portions; retaining means externally or said body anddisposed in said slots and engageable with said gripping members to holdsaid gripping members in retracted position in said bores; and means`for shifting said retaining means longitudinally of said body and insaid slots `from holding relation to said gripping members to permitoutward expansion of said gripping members.

I5. In apparatus adapted to be anchored in a well casing disposed in awell bore: a -body lhaving a plurality of bores therein opening to theinterior of Said body; gripping members in said bores expandableoutwardly against the well casing in response to fluid pressure withinsaid body and bores; said gripping members having longitudinal slots intheir outer portions, retaining means externally of said body anddisposed in said slots and engageable with said gripping members tohol-d said gripping members in retracted position in said bores; meansfor shifting said retaining means ylongitudinally of said body and insaid slots `from holdin-g relation to said gripping members to permitoutward expansion of saidgripping members; and means yfor shifting saidretaining means longitudinally of said body and 4in said slots toretract said grip-ping members and hold said gripping members inretracted position.

i6. In apparatus adapted to be anchored in a well casing disposed in awell bore: a body lhaving a plurality of bores therein opening to theinterior of said body; gripping members in said 'bores expandableoutwardly against the well casing in response to fluid press-ure withinsaid body and lbores; said gripping members having longitudinal slots intheir outer portions; a mand-rel movable within said body; retainingmeans externally of said body and -disposed in said slots and engageablewith said gripping members to hold said gripping mem-bers in retractedposition in said bores; and means operatively connected to said 4mandreland movable thereby `for shift-ing said retaining means longitudinallyof said body and in said sl-ots from holdin-g relation to said grippingmembers to permit outward expansion of said gripping members.

17. In apparatus adapted to Abe anc-hored in a well casing disposed in awell bore: a body having a plurality of bores therein opening to theinterior of said body; gripping members in said bores expandableoutwardly against the well casing in response to Huid pressure withinlsaid body and bores; said gripping members having longitudinal sl-otsin their outer portions and detents projecting in a lateral outwarddirection from the inner portions of said slots; retaining meansexternally of said body including bars in said slots engageable withsaid detents to hold said gripping Imembers in yretracted position insaid bores; and means for shifting said retaining means longitudinallyof said body in one -direction to shift said bars in said slots `fromengagement with said detents to permit outward expansion of saidkgripping members.

i8. In apparatus adapted to be anchored in a well casing disposed in awell bore: a body having a plurality of bores therein opening to theinterior of said body; gripping members in said bores expandableoutwardly against the well casing in response to fluid pressure within`said body and bores; said gripping members having longitudinal slots intheir outer portions and detents projectin-g in a lateral outwarddirection lfrom the inner portions of `said slots; retain-ing meansexternally of said body inc-luding 'bars in said slots engageable withsaid detents to hold said gripping members in retracted position in saidbores; means -or shifting said retaining means longitudinally of saidbody in one direction to shift said bars in said slots yfrom engagementwith said detents to permit outward expansion of said gripping members;and means for shifting said retaining means in the opposite longitudinaldirection to reengage said bars with said detents to `retract sa-idgripping members and hold said gripping members in retracted position.

19. In apparatus adapted to be anchored in a well casin-g disposed in awell bore: a body having a plurality of bores therein opening to theinterior of said body; gripping members in said bores expandableoutwardly against the well casing in response to uid pressure withinIsaid body and bores; said gripping members having longitudinal slots intheir outer portions and detents projecting in a lateral outwarddirection `from the inner portions of said slots; retaining meansexternally of said body including ba-rs in said slots engageable withsaid detents to hold said gripping members in retracted position in saidbars; a mandrel movable within said body; and means operativelyconnected to said mandrel and movable thereby for shifting saidretaining means longitudinally of said body in one direction to shiftsaid bars in 'said slots from 13 engagement with said detents to permitoutward expans-ion olf said `gripping members.

20. In apparatus adapted to be ancho-red in a Well casing disposed 'in awell bore: a body having a plurality of bores therein opening to theinter-ior of said body; gripping members in said bones expandableoutwardly against the well casing in Iresponse to iluid pressure withinsaid body and bores; said gripping members having lon -gitudinal slotsin their outer portions and detents project ing in a lateral outwarddirection from the inner portions of said slots; retaining meansexternally of said body including bars in said slots engageable withsaid detents to hold said Igripping members in Aretracted position insaid bores; a mandrel movable Within said body; means operativelyconnected to said mandrel and movable thereby for shifting saidretaining means longitudinally of said body in one direction to shiftsaid bars in said slots from eng-agement with said detents to permitoutward eXpansion of sa-id gripping members; and means for shifting 14said retaining means in t-he opposite longitudinal direction to reengageIsaid bars with sa-id detents to retract said gripping members and holdsaid gripping members in .retracted position.

References Cited by the Examiner CHARLES E. OCONNELL, Primary Examiner.

JACOB L. NACKENOFF, Examiner.

I. A. LEPPINK, Assistant Examiner.

1. IN APPARATUS ADAPTED TO BE ANCHORED IN A WELL CASING DISPOSED IN A WELL BORE: A BODY HAVING A PLURALITY OF BORES THEREIN OPENING TO THE INTERIOR OF SAID BODY; GRIPPING MEMBERS IN SAID BORES EXPANDABLE OUTWARDLY AGAINST THE WELL CASING IN RESPONSE TO FLUID PRESSURE WITHIN SAID BODY AND BORES; RETAINING MEANS ENGAGING SAID GRIPPING MEMBERS FOR HOLDING SAID GRIPPING MEMBERS IN RETRACTED POSITION IN SAID BORES, SAID RETAINING MEANS BEING MOVABLE LONGITUDINALLY OF SAID BODY FROM HOLDING ENGAGEMENT WITH SAID GRIPPING MEMBERS; AND MEANS FOR SHIFTING SAID RETAINING MEANS IN A DIRECTION LONGITUDINALLY OF SAID BODY FROM HOLDING RELATION TO SAID GRIPPING MEMBERS TO PERMIT THEIR OUTWARD EXPANSION. 